Radius Calculator

Radius Calculator allows you to calculate the radius, central angle, arc length, and circumference from the span / chord and rise of an arc segment. Built-in unit converter makes it to work with any length unit (including inches, feet, centimeters, meters, and many more).

Simply enter the span / chord and the rise to arc in your choice of units. Then pick the output unit unit and the radius, central angle, arc length, and circumference are instantly computed.

Designed for the multiple trades in the construction industry, this calculator is great for any craftsman who needs to find properties of a circle given curve measurements. In particular, Radius Calculator is perfect carpenters or cabinet makers who deal with curved walls.

Note: There is no closed form solution for the central angle and we use a common approximation for that calculation. This method is very accurate for small angles and about 10% off on large angles approaching 180 degrees.